6.10 control cables Flashcards
(105 cards)
1
Q
Where are cables used?
A
Smaller aircraft’s to transmit force to flight controls
2
Q
What the advantages of cables?
A
ightweight
Flexible
Strong
High mechanical efficiency
3
Q
What can cables transmit power without gaining?
A
Backlash
4
Q
Why must tension be adjusted frequently?
A
Because the cables stretch over a period of timed
5
Q
What disadvantage are cables prone to?
A
Prone to wear
6
Q
What can cause tension to vary?
A
Temperature change
7
Q
When cables stretch, do they become deformed?
A
No
8
Q
Does vibration effect control cables?
A
no
9
Q
Why are failures of in control cables rare?
A
Because of the amount of wires in a cable
10
Q
All aircraft control cables are what in terms of manufacturing?
A
Preformed
11
Q
What is the basic element of the control cable?
A
A strand
12
Q
What is a strand?
A
A number of wires braided together
13
Q
What do strands bundled together form?
A
A cable
14
Q
When does wires and strands’ tendency to uncoil reduce?
A
When the wires and strands are twisted in the opposite direction, but the cables are wrapped in the same direction
15
Q
What is the opposite direction twist also called?
A
A regular lay
16
Q
If the strands are twisted around a central core, what is it called?
A
Lang lay
17
Q
How are cables designated?
A
To the number of strands
18
Q
What do aircraft cables diameter vary to?
A
1.6mm and 9.53mm
19
Q
What does 1X7 mean?
A
One strand compromised of 7 different wires
20
Q
What is involved in non flexible wires?
A
1 X 7
1 X 19
21
Q
Where are non flexible wires used?
A
Straight runs where the cables don’t pass over pulleys
22
Q
What is involved in flexible wires?
A
7 X 7
23
Q
Where are flexible cables used?
A
Straight runs and where large pulleys are being used
24
Q
What does extra flexible cables involve?
A
7 x 19
25
Where are extra flexible cables used?
Trim and flight controls (Areas that require a change in direction)
26
Terminal fitting are usually of what type?
The swage type
27
What are threaded end, fork end and eye ends used for?
To connect to turnbuckles and other linkage
28
What are ball terminals used for?
Attaching cables to quadrants, and other connections where space is limited
29
Where are single shank ball ends located?
On the end of a a cable
30
Where are double shank ball ends used?
Either on the ends of a cable, or in the centre
31
Where are thimble and bushing fitting used?
Terminal fittings where supplies are limited but the repair is needed
32
How can you help a cable compensate for temperature change?
By fitting cable tension regulators
33
What do cable tension regulators do?
Extension or compression of springs to adjust to cable quadrant positionings
34
What is dangerous about disconnecting cables?
They can spring back becsuse of the tension
35
What must aircraft cable regulators be in accordance with?
The AMM
36
Where are turnbuckles used?
Where tension is required
37
What must you do to a turnbuckle when you're done with it?
It must be safetied or locked
38
What else is used to secure turnbuckles?
Single or double wrap method which used lock wire
39
What is a turnbuckle assembly?
A mechanical screw device consisting of two threaded terminals and a threaded barrel
40
What are turnbuckles used for?
To make minor adjustments and adjust cable tension
41
What is important when screwing a turnbuckle?
How many threads can be exposed?
Turn both turnbuckles an equal amount of turned into the barrel until no more than 3 threads are exposed
42
How can the end of the barrel with left hand threads be identified?
By a groove or knurl around the end of the barrel
43
How are lock clad cables produced?
By swaging aluminium onto galvanised or stainless aircraft cable
44
What is the code for lock clad cables?
7 X 7
7 X 19
45
Why was lock clad developed?
To eliminate sagging and wear in long aircraft cables
46
Why is lock clad used?
Stress is reduced
Sag is eliminated
Vibration is reduced
Aluminium tubing stops abrasion of outer wires
47
What are pulleys used for?
To guide cables and change the direction of cable movement
48
What is the state of pulley bearings before use?
Pre lubricated and sealed
49
What is used to support the pulley?
A bracket
50
How are cables passing over the pulleys kept in place?
By a guard
50
What is the guard pin?
A Clevis pin held in place by a split pin and washer to prevent damage
51
What are guards used for?
To prevent slipping or jamming
52
When is a fair lead or grommet used?
When there is possibility or the aircraft contacting the structure
52
What are push rods used for?
As links in the flight control system to give push pull motion
52
Where can push rods be adjusted from?
Both ends or one end
52
What does a push rod consist of?
A tube with threaded rod ends
52
What permits attachment of the tube to flight control system parts?
The rod end or clevis
53
What prevents the rod end or coves from unloosening?
A check it
54
How can control rods on bearings be prevented from loosening?
The flange of the rod end is interposed between the ball race and the anchored end
55
What are bell cranks and quadrants be made out of?
Heat treated aluminium
56
Where are ball cranks and quadrants used?
In push pull tubing systems to change direction of travel and mechanical advantage
57
What can cause a delay in response?
Wear where connection is
58
Why are torque tubes installed?
When an angular or twisting motion is required
59
What are aircraft cables only capable of in terms of forces?
Pulling
60
When a two directional force is needed, the use of what is needed?
When a two directional force is needed, the use of what is needed?
61
What does cable control consist of?
A single cable passing through a covering (conduit)
62
Why is straightening of a conduit prevented even though a pull force will try to bend it back into place?
Because the end fittings are fixed
63
What is a Bowden cable?
An inner steel cable which moves linearly and is free to slide
64
What do small aircraft use the Bowden cables for?
Throttle or fuel mixture control
65
When do Bowden cables fail to function smoothly?
When water or contaminants enter
66
What are teleflex controls used for?
To operate components
67
How do teleflex transmit force?
Through a push and pull motion
68
If the teleflex is not long enough, what can be used for connection?
Rigid cables or linkages
69
What else may be used as a thread?
A helix winding
70
Are cables interchangeable with each other on aircraft?
No
71
What way does DS 23/2 (No.2) turn?
Left no helix
72
What is DS 23/2 made out of?
steel
73
What way does DS 380 turn?
Right
74
What does DS 380 not have?
Compression wire
75
What is different about the diameter in DS 380?
Greater diameter than the core
76
Where is DS 169330 used?
Hot areas (it's made of stainless steel)
77
What is the transmitting end of a control usually fitted with?
A wheel consisting of a hand operating gear
78
When can a push pull operating handle be used?
Where the loading is light and straight
79
What are swivel joints used for?
To take up angular movements
80
In a single entry unit, what is the rotary travel limited to?
270 degrees
81
When is a double entry used?
When greater travel is required
82
In double entry, what is the cable degree?
90 degrees 120 degrees 180 degrees
83
What is the short cable that comes out from the back of the conduit known as?
A spent travel tube
84
What is a straight lead unit?
The cable passes straight through the unit and engages on a few teeth on the wheel
85
What are straight lead units not suitable for?
Heavy loads
86
What are junction box units used for?
To reverse direction or to branch a run of cables
87
What does anti torsion tubes do?
Not allow the cable to turn in the conduit so doesn't change the relative adjustments
88
Where can swivel joints be installed?
Where rotary movement of the control does not exceed 90 degrees
89
What do swivel joints consist of?
A ball and a socket
90
When are sliding end fittings used?
When it's not necessary to convert the push pull motion into rotary
91
What do slide fittings comprise of?
Guide tube and end fittings
92
What are quick break units?
Facilitate removal of components without disturbing the control
93
What do conduit connectors have?
Nipples
94
What are conduit connectors similar in construction to?
All metal pipe couplings
95
What is a torsion drive?
The final linear movement of the control is converted to a rotary action using the distributor box
96
What is the torsion drive similar to?
The normal flexible drive
97
What is the distributor box similar to?
A receiver unit
98
In a distributor box, how can you convert the rotary motion of the torsion drive to the linear movement of a trmiming tab?
A sprocket driven screw jack
99
How is the left hand thread on a turnbuckle identified?
By a groove at the end of a barrel
100
Which type of cable is used in aircraft control and trim systems?
Extra flexible wires
